SPC Jan 4, 2024 Day 4-8 Severe Weather Outlook

[NorthGeorgiaWX]

Day 4-8 Outlook

Day 4-8 Convective Outlook  
NWS Storm Prediction Center Norman OK
0400 AM CST Thu Jan 04 2024

Valid 071200Z - 121200Z

...DISCUSSION...
Minimal severe potential remains evident across the CONUS on Day
4/Sunday as a cold front clears much of the FL Peninsula. Another
pronounced upper trough/low is forecast to eject across the southern
Plains and Southeast from Day 5/Monday into Day 6/Tuesday. Low-level
moisture should return northward in earnest from Sunday night into
Monday ahead of this cyclone, with at least low 60s surface
dewpoints probably reaching parts of east TX into southern LA by
Monday afternoon. A deepening surface low is progged to develop from
the TX Panhandle to the Mid-South by Tuesday morning, with
associated cold front expected to sweep eastward across east TX and
the lower MS Valley.

There is still some uncertainty regarding how much instability will
develop inland across these areas due to the possibility of
substantial convection over the northern Gulf of Mexico impeding
low-level moisture advection to some extent. Even so, GEFS mean
forecast MLCAPE of 500-1000 J/kg from east TX into LA and southern
MS/AL should be more than enough to support a severe thunderstorm
threat given the presence of very strong deep-layer shear. The
threat for supercells and short line segments capable of producing
tornadoes, large hail, and damaging winds should spread eastward
across this area from Monday afternoon through Monday night and
early Tuesday morning. Some adjustments have been made to the
northern and eastern extent of the 15% severe area for Monday across
MS/AL and the FL Panhandle based on latest deterministic and
ensemble guidance. This includes the northward extent of GEFS and
EPS mean surface dewpoints reaching into at least the low 60s.

A 15% severe delineation has also been introduced for Tuesday across
parts of north/central FL and southern GA. This will be a
continuation of the threat from Monday farther west, as the mature
upper cyclone is forecast to move quickly northeastward from the
lower MS Valley to the TN/OH Valley and Mid-Atlantic by Tuesday
evening. Very strong mid-level flow will likely aid in ample
deep-layer shear to support continued convective organization. While
some concern also exists on Tuesday regarding the potential for
widespread thunderstorms over the northern Gulf of Mexico,
medium-range guidance remains in good agreement that mid to upper
60s surface dewpoints will likely advect northward across much of FL
and into southern GA ahead of the surface cold front. Low-level
shear appears strong enough for updraft rotation and a tornado
threat. Very strong wind fields overall should also support a threat
for severe/damaging winds as convection spreads eastward along/ahead
of the front Tuesday.

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